In September of 1992 a collaboration between the NIDR and the Air Force Medical Corps was established to conduct a comprehensive study on the effects of mercury vapor from dental amalgams as a component of the Air Force Health Study (AFHS) of Vietnam Veterans. The surrogate measure used to assess exposure in this study is the total number of amalgam surface years for a study participant. Several health outcomes are being investigated as part of this study protocol. These include information on the neurological system, renal system, endocrine system, immunological system, and several psychological characteristics of study participants. The clinical examinations were completed by the end of March 1993. There was a 98% compliance rate for the NIDR amalgam study among potential AFHS participants. Blood and urine samples were collected from all participants as part of the study protocol and are being analyzed by Mayo Clinic's laboratory and validated by an expert reference laboratory. Lead blood assays were also performed for a 15% subsample of these participants. The 1992 clinical data is currently being processed and will be available to the NIDR shortly. Immediate attention will be given to a study involving the associations between Hg concentrations in urine and/or blood and dental amalgam exposure. A detailed analytical plan is currently under development for the main study involving the analysis of major health outcome variables. This protocol will be drafted by NIDR staff, reviewed and revised by senior Air Force Health Study investigators, and co-authorship of study protocol finalized in early fall on 1993.